I had a dream i was bitten by a Cobra on the hand. I was helping a guy milk it.
Is this a death warning dream?

I doubt it. Do you have any reason to think that you are going to die soon? Do you engage in dangerous, potentially life-threatening activities? Are you very ill? Do you have family members that died young from inheritable conditions?

Helping a guy milk a cobra is a dangerous task. The dream might be your unconscious' way of pointing out a threat in your life - not necessarily a physical threat; maybe someone is going to hurt you emotionally - and trying to tell you to pay attention and be careful.